Blood pressure measurement device

ABSTRACT

A blood pressure measurement device having an attach portion including: an opening portion provided at a position opposite a region where one artery of a wrist is found and an end surface that curves conforming to a shape in a circumferential direction of a portion of the wrist; a fastener on the attach portion; and a sensing body including: a sensor unit opposite the opening portion, the sensor unit including a sensor module that comes into contact with the region where the one artery of the wrist is found and an air bag that presses the sensor module toward the wrist by expanding when the device is worn on the wrist, a case that houses the sensor module to allow the sensor module to move in one direction with respect to the opening portion, and a biasing member that biases the sensor module in a direction away from the wrist.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the U.S. national stage application filed pursuantto 35 U.S.C. 365(c) and 120 as a continuation of International PatentApplication No. PCT/JP2019/020051, filed May 21, 2019, which applicationclaims priority from Japanese Patent Application No. 2018-099735, filedMay 24, 2018, which applications are incorporated herein by reference intheir entireties.

TECHNICAL FIELD

The present invention relates to a blood pressure measurement device formeasuring blood pressure.

BACKGROUND ART

In recent years, blood pressure measurement devices for measuring bloodpressure are being used to monitor health status at home, as well as inmedical facilities. In such blood pressure measurement devices, forexample, known technologies using the oscillometric method, thetonometry method as described in JP H01-288228 A, and the like are used.A blood pressure measurement device using the oscillometric methoddetects vibration of the artery wall and measures blood pressure byusing pressure sensor to detect the pressure of a cuff wrapped aroundthe upper arm or wrist of a living body.

Also, a blood pressure measurement device using the tonometry methodmeasures blood pressure by bringing a sensor module including aplurality of pressure sensors into contact with a region of the wristwhere the artery is found. Such blood pressure measurement devices usingthe tonometry method measures blood pressure per beat, for example, bypressing a radial artery, one artery of the arm, with a sensor module toform a flat portion in the artery, and measuring the pressure pulse wavewith the interior and exterior of the radial artery in a balanced state.

CITATION LIST Patent Literature

Patent Document 1: JP H01-288228A

SUMMARY OF INVENTION

Technical Problem

It is conceivable that a blood pressure measurement device using thetonometry method described above, to form a flat portion in the artery,uses a drive mechanism to press the sensor module against the wrist to aposition whereby a flat portion is formed in the artery. The drivemechanism brings the sensor module into contact with the wrist from aposition spaced apart from the wrist, for example, and further moves thesensor module. For example, as such a drive mechanism, a configurationis conceivable in which the sensor module is moved toward the wrist byexpanding an air bag to press against the sensor module. However, as theair bag expands and the stroke amount of the sensor module increases,the pressing force of the air bag pressing against the sensor moduleproblematically decreases. When the pressing force of the air bagpressing against the sensor module decreases, an unfavorable flatportion may be formed in the artery.

Thus, an object of the present invention is to provide a blood pressuremeasurement device that can suitably press the sensor module against thewrist with a simple configuration.

Solution to Problem

According to an aspect, provided is a blood pressure measurement device,including:

-   an attach portion including:-   an opening portion provided at a position opposite a region where    one artery of a wrist is found and-   an end surface that curves conforming to a shape in a    circumferential direction of a portion of the wrist;-   a fastener provided on the attach portion; and-   a sensing body including:-   a sensor unit disposed opposite the opening portion, the sensor unit    including a sensor module that comes into contact with the region    where the one artery of the wrist is found and an air bag that    presses the sensor module toward the wrist by expanding when the    device is worn on the wrist,-   a case that houses the sensor module in a manner allowing the sensor    module to move in one direction with respect to the opening portion,    and-   a biasing member that biases the sensor module in a direction toward    the wrist.

Here, the region in which one artery of the wrist is found is the regionin which the radial artery or the ulnar artery of the wrist is found andpreferably is the region in which the radial artery is found.

According to this aspect, the biasing member is configured to bias thesensor module toward the wrist. Thus, during blood pressure measurement,the biasing member also presses the sensor module toward the wrist whenthe sensor module is pressed toward the wrist by the air bag. Thus, theblood pressure measurement device can suitably press the sensor moduleagainst the wrist by the biasing member assisting in pressing, even ifthe amount of stroke of the sensor module increases and the pressingforce at which the air bag presses the sensor module is reduced. As aresult, the blood pressure measurement device can form a preferred flatportion in the artery.

Provided is a blood pressure measurement device according to the bloodpressure measurement device of the aspect described above, wherein thebiasing member

-   biases the sensor module in the direction toward the wrist when an    end of the sensor module is located on a side of the wrist from a    neutral point, the neutral point being a predetermined position with    respect to the opening portion, and biases the sensor module in a    direction away from the wrist when the end of the sensor module is    located at a position further away from the wrist than the neutral    point.

According to this aspect, the biasing member biases the sensor module ina direction toward the wrist with force along one direction, with theneutral point of the sensor module acting as the boundary, when thesensor head cover is positioned closer to the wrist than the neutralpoint. According to this configuration, when the blood pressuremeasurement device is used for blood pressure measurement, the air bagand the biasing member press the sensor module toward the wrist,allowing the sensor head cover to be suitably pressed against the wrist.

Also, according to this configuration, the biasing member biases thesensor module in a direction away from the wrist when the end of thesensor module is at a position separated from the wrist further than theneutral point. Thus, after blood pressure measurement, the sensor moduleis biased and moved by the bias member in a direction away from thewrist with force along one direction, and the sensor module is locatedinside the case more so than the opening portion. Thus, when removingthe worn blood pressure measurement device, the sensor module does notproject outward.

Provided is a blood pressure measurement device according to the bloodpressure measurement device of the aspect described above, wherein theneutral point is a position where the end of the sensor module projectsfrom the opening portion.

According to this aspect, the neutral point is at a position where theend of the sensor module projects from the opening portion, and thus thesensor module can be moved to a position further away from the wristthan the neutral point using the reaction force from the wrist. Thus,the biasing direction of the biasing member can be switched from thedirection of pressing the sensor module toward the wrist to a directionof biasing the sensor module away from the wrist.

Provided is a blood pressure measurement device according to the bloodpressure measurement device of the aspect described above, wherein thebiasing member is a torsion spring.

According to this aspect, the sensor module is biased with the biasmember with a simple configuration including a torsion spring. Thus, anincrease in manufacturing cost can be prevented.

Provided is a blood pressure measurement device according to the bloodpressure measurement device of the aspect described above, wherein aplurality of the torsion springs are provided.

According to this aspect, because a plurality of the torsion springs areprovided, the size of the each of the plurality of torsion springsneeded to create a desired biasing force can be made small and used assuch, compared to a configuration in which a single torsion spring isprovided. Thus, the sensor device can keep the space and configurationsmall for installing and supporting the torsion springs.

Provided is a blood pressure measurement device according to the bloodpressure measurement device of the aspect described above, wherein twoof the torsion springs are provided on either side of the sensor modulein a direction orthogonal to the circumferential direction of the wristwhen the device is worn on the wrist, and one end of each of the torsionsprings is fixed to the sensor module and the other end of each of thetorsion springs is fixed to the case.

According to this aspect, the sensor device includes a pair of thetorsion springs disposed with point symmetry on either side of thesensor module. Thus, the torsion springs can uniformly apply a biasingforce to the sensor module. This allows the sensor device to apply thebiasing force of the torsion springs to the sensor module along themovement direction of the sensor module.

Provided is a blood pressure measurement device according to the bloodpressure measurement device of the aspect described above, wherein thebiasing member is formed from a resin material and deforms due to anexternal force in one direction and restores its shape in a directionopposite to the direction in which the external force is applied.

According to this aspect, the biasing member can be formed from a resinmaterial, making design and manufacture easy.

Advantageous Effects of Invention

The present invention provides a blood pressure measurement device thatcan move the sensor module back and forth in one direction with a simpleconfiguration.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view illustrating the configuration of a bloodpressure measurement device according to an embodiment of the presentinvention.

FIG. 2 is a block diagram illustrating the configuration of the bloodpressure measurement device.

FIG. 3 is a perspective view illustrating the configuration of a sensordevice of the blood pressure measurement device.

FIG. 4 is a perspective view illustrating the configuration of a portionof the sensor device of the blood pressure measurement device.

FIG. 5 is a perspective view illustrating the configuration of a sensorunit of the blood pressure measurement device.

FIG. 6 is a perspective view illustrating the configuration of thesensor unit with a side wall omitted.

FIG. 7 is a perspective view illustrating the configuration of thesensor unit with a side wall omitted.

FIG. 8 is a plan view illustrating the configuration of the sensor unit.

FIG. 9 is a cross-sectional view illustrating the configuration of thesensor module and an air bag of the sensor unit.

FIG. 10 is a cross-sectional view illustrating the configuration of thesensor module and the air bag.

FIG. 11 is a cross-sectional view illustrating the configuration of thesensor module and the air bag.

FIG. 12 is an explanatory diagram illustrating the operation of thesensor unit.

FIG. 13 is a cross-sectional view illustrating the configuration of thesensor module and the air bag.

FIG. 14 is a cross-sectional view illustrating the configuration of theblood pressure measurement device in a state of being attached to thewrist.

FIG. 15 is a cross-sectional view illustrating the configuration of theblood pressure measurement device in a state of being attached to thewrist.

FIG. 16 is a cross-sectional view illustrating the configuration of theblood pressure measurement device in a state of being attached to thewrist.

FIG. 17 is a cross-sectional view illustrating the configuration of thesensor module of the sensor unit.

FIG. 18 is a plan view illustrating the configuration of the sensormodule.

FIG. 19 is an explanatory diagram illustrating an example of theposition adjustment of the sensor unit of the blood pressure measurementdevice.

FIG. 20 is a flowchart illustrating an example of blood pressuremeasurement using the blood pressure measurement device.

FIG. 21 is an explanatory diagram illustrating an example of bloodpressure measurement using the blood pressure measurement device.

FIG. 22 is an explanatory diagram illustrating an example of bloodpressure measurement using the blood pressure measurement device.

FIG. 23 is an explanatory diagram illustrating an example of bloodpressure measurement using the blood pressure measurement device.

FIG. 24 is an explanatory diagram illustrating the relationship betweenstroke and pressing force of the blood pressure measurement device.

FIG. 25 is an explanatory diagram illustrating the relationship betweenstroke and pressing force of the blood pressure measurement device.

FIG. 26 is a cross-sectional view illustrating the configuration of abiasing member of a sensor unit according to another embodiment of thepresent invention.

FIG. 27 is a perspective view illustrating the configuration of a bloodpressure measurement device according to another embodiment of thepresent invention.

FIG. 28 is a block diagram illustrating the configuration of the bloodpressure measurement device.

FIG. 29 is a perspective view illustrating the configuration of a bloodpressure measurement device according to another embodiment of thepresent invention.

DESCRIPTION OF EMBODIMENTS First Embodiment

An example of a blood pressure measurement device 1 according to thefirst embodiment of the present invention is described below using FIGS.1 to 18.

FIG. 1 is a perspective view illustrating the configuration of the bloodpressure measurement device 1 according to an embodiment of the presentinvention in a state in which a body fastener 16 is closed. FIG. 2 is ablock diagram illustrating the configuration of the blood pressuremeasurement device 1. FIG. 3 is a perspective view illustrating theconfiguration of a sensor device 5 of the blood pressure measurementdevice 1 in a state in which a sensing body 42 is open. FIG. 4 is aperspective view illustrating the configuration of the blood pressuremeasurement device 1 with a sensor unit 52 removed from the sensordevice 5. FIG. 5 is a perspective view illustrating the configuration ofthe sensor unit 52 of the blood pressure measurement device 1. FIG. 6 isa perspective view illustrating the configuration of the sensor unit 52with a side wall omitted. FIG. 7 is a perspective view illustrating theconfiguration of the sensor unit 52 with a side wall omitted. FIG. 8 isa plan view illustrating the configuration of the sensor unit 52.

FIG. 9 is a cross-sectional view illustrating the configuration of asensor module 63 and an air bag 62 of the sensor unit 52 taken along across-section line IX-IX in FIG. 8. FIG. 10 is a cross-sectional viewillustrating the configuration of the sensor module 63 and the air bag62 taken along a cross-section line X-X in FIG. 8. FIG. 11 is across-sectional view illustrating the configuration of the sensor module63 and the air bag 62 taken along a cross-section line XI-XI in FIG. 8.FIG. 12 is an explanatory diagram illustrating the operation of thesensor unit 52. FIG. 13 is a cross-sectional view illustrating theconfiguration of the sensor module 63 and the air bag 62 of the sensorunit 52 taken along a cross-section line XIII-XIII in FIG. 9. FIGS. 14to 16 are cross-sectional views illustrating the configuration of theblood pressure measurement device 1 in a state of being attached to awrist 100. FIG. 17 is a cross-sectional view illustrating theconfiguration of the sensor module 63 of the sensor unit 52. FIG. 18 isa plan view illustrating the configuration of the sensor module 63 ofthe sensor unit 52.

Note that in the drawings, a radial artery of a wrist 100 is denoted as110, a radius is denoted as 111, an ulnar artery is denoted as 112, anulna is denoted as 113, and a tendon is denoted as 114.

The blood pressure measurement device 1 is an electronic blood pressuremeasurement device that is attached to the wrist 100 of a living bodyand calculates a blood pressure value from the pressure of the radialartery 110. As illustrated in FIGS. 1 to 18, the blood pressuremeasurement device 1 includes a device body 4 and the sensor device 5.For example, the blood pressure measurement device 1 has a configurationin which the sensor device 5 is attached to a region of the wrist 100where the radial artery 110 is found and in which the device body 4 isattached to the wrist 100 adjacent to the sensor device 5 on the elbowside.

The blood pressure measurement device 1, by pressing the radial artery110 with the sensor device 5, measures the pressure of the pressurepulse wave per heart beat that changes in conjunction with the heartrate of the radial artery 110. In addition, the blood pressuremeasurement device 1 executes, via the device body 4, processing basedon the tonometry method on the measured pressure and obtains the bloodpressure.

As illustrated in FIGS. 1 and 2, the device body 4 includes: a body case11, an operation portion 12, a display portion 13, a pump 14, a controlboard 15, and the body fastener 16. Also, for example, the device body 4may be provided with a cuff on the body fastener 16 that is configuredto compress the wrist 100 during blood pressure measurement.

The body case 11 houses: a portion of the operation portion 12, aportion of the display portion 13, and the control board 15 and exposes:a portion of the operation portion 12 and a portion of the displayportion 13 from the outer surface. In addition, the body fastener 16 isattached to the body case 11.

The operation portion 12 is configured to receive an instruction inputfrom a user. For example, the operation portion 12 includes: a pluralityof buttons 21 provided on the body case 11 and a sensor that detectsoperation of the buttons 21. Note that the operation portion 12 may beprovided on the display portion 13 as a touch panel. When operated bythe user, the operation portion 12 converts an instruction into anelectrical signal. The sensor that detects operation of the buttons 21is electrically connected to the control board 15 and outputs anelectrical signal to the control board 15.

The display portion 13 is disposed in the body case 11 and is exposedfrom the outer surface of the body case 11. The display portion 13 iselectrically connected to the control board 15. The display portion 13is, for example, a liquid crystal display or an organicelectroluminescent display. The display portion 13 displays variousinformation including measurement results such as date and time; bloodpressure values like maximum blood pressure and minimum blood pressure;heart rate; and the like.

The pump 14 is, for example, a piezoelectric pump. The pump 14 includesa tube 14 a connected to the sensor device 5 for compressing air andsupplying compressed air to the sensor device 5 via the tube 14 a. Thepump 14 is electrically connected to the control board 15.

As illustrated in FIG. 2, the control board 15 includes a communicationunit 31, a storage unit 32, and a control unit 33, for example. Thecontrol board 15 is configured by the communication unit 31, the storageunit 32, and the control unit 33 being mounted on the board. Also, thecontrol board 15 is connected to the sensor device 5 via a cable 15 a.The cable 15 a runs from inside the body case 11 to outside the bodycase 11 via a portion of the outer surface of the body case 11. Forexample, the cable 15 a runs from inside the body case 11 to the sensordevice 5 via an opening formed in a side surface of the body case 11.

The communication unit 31 is configured to transmit and receiveinformation from an external device wirelessly or via a wire. Thecommunication unit 31 transmits information, such as informationcontrolled by the control unit 33, measured blood pressure values,pulse, and the like, to an external device via a network and receives aprogram for software update or the like from an external device via anetwork and sends this to the control unit.

In the present embodiment, the network is, for example, the Internet,but no such limitation is intended. The network may be a network such asa Local Area Network (LAN) provided in a hospital or may be a directwired communication with an external device, using a cable or the likeincluding terminals of a predetermined protocol such as USB. Thus, thecommunication unit 31 may include a plurality of wireless antennas,micro-USB connectors, or the like.

The storage unit 32 pre-stores: program data for controlling the entireblood pressure measurement device 1; settings data for configuringvarious functions of the blood pressure measurement device 1;calculation data for calculating blood pressure values and pulse fromthe pressure measured by pressure sensitive elements 71 c; and the like.Furthermore, the storage unit 32 stores information such as: thecalculated blood pressure value; pulse; time series data in which thiscalculated data and time are associated; and the like.

The control unit 33 is composed of, for example, a single or a pluralityof central processing units (CPU). The control unit 33 controls theoperation of the entire blood pressure measurement device 1 and executeseach processing on the basis of the program data. The control unit 33 iselectrically connected to the operation portion 12, the display portion13, the pump 14, and the sensor device 5, controls the operation of eachconfiguration, transmits and receive signals, and supplies power.

The body fastener 16 includes, for example, one or a plurality ofband-like bands; and a fixing member such as a hook-and-loop fastenerthat secures the band wrapped around the wrist 100. The body fastener 16fixes the body case 11 to the wrist 100.

With the device body 4 having such a configuration, by the control unit33 executing processing using the program data stored in the storageunit 32, blood pressure data can be continuously generated from thepulse waves of the radial artery 110 detected by the sensor device 5.The blood pressure data includes data of blood pressure waveformscorresponding to the waveforms of measured pulse waves. The bloodpressure data may further include time series data of a blood pressurefeature value (blood pressure value). The blood pressure feature valueincludes, for example and without limitation, systolic blood pressure(SBP) and diastolic blood pressure (DBP). The maximum value in the pulsewave waveform per heart beat corresponds to systolic blood pressure, andthe minimum value in the pulse wave waveform of per heart beatcorresponds to diastolic blood pressure.

In this embodiment, the device body 4 measures the pressure pulse waveas a pulse wave by the tonometry method. Here, the tonometry methodrefers to a method for pressing the radial artery 110 from above theskin with appropriate pressure, forming a flat portion in the artery,and measuring the pressure pulse wave with the sensor device 5 in abalanced state between the interior and the exterior of the radialartery 110. According to the tonometry method, a blood pressure valueper heart beat can be acquired.

As illustrated in FIGS. 1, 3, and 4, the sensor device 5 includes: anattach portion 41, the sensing body 42, and a fastener 43.

The attach portion 41 includes a main surface that has a shape thatconforms to the circumferential direction of the wrist 100 in the regionwhere the radial artery 110 of the left wrist 100 is found. As aspecific example, the attach portion 41 includes: a base portion 41 athat curves conforming to the shape in the circumferential direction ofthe wrist 100 in the region in contact with the wrist 100; an openingportion 41 b formed in the base portion 41 a; an attachment portion 41 cprovided on the base portion 41 a for attaching the sensing body 42; anda cushion 41 d provided on a main surface of the base portion 41 a thatcomes into contact with the wrist 100.

The base portion 41 a is configured to be elongated in one direction.The base portion 41 a is disposed on a palm side of wrist 100 and on aside portion side on the radius 111 side of the wrist 100, and the mainsurface disposed on the wrist 100 side curves conforming to the shape inthe circumferential direction of the palm side of the wrist 100 and theside portion side on the radius 111 side of the wrist 100. Furthermore,at least the outer circumferential edge side of the main surface of thebase portion 41 a comes into contact with the sensing body 42.

The opening portion 41 b is provided in a central region of the baseportion 41 a and is formed with a size of one or a plurality of fingers.That is, the opening portion 41 b is formed with a size that allows theregion where the radial artery 110 of the wrist 100 is exposed from theopening portion 41 b to be palpated by a finger, when the sensor device5 is attached to the wrist 100, and that allows a portion of the sensingbody 42 to come into contact with the wrist 100.

The attachment portion 41 c is provided on a main surface of the baseportion 41 a opposite the surface facing the wrist 100 and provided onan end side of the base portion 41 a in the longitudinal direction. Theattachment portion 41 c supports the sensing body 42 and is configuredto move the sensing body 42 in a direction away from the base portion 41a and a direction toward the base portion 41 a. As a specific example,the attachment portion 41 c is a journal-like portion that rotatablyjournals the sensing body 42 about an axis. For example, the attachmentportion 41 c is integrally formed with the base portion 41 a.

The cushion 41 d is, for example, an elastic body configured in a sheetshape from a foaming resin material provided on a main surface of thebase portion 41 a that comes into contact with the wrist 100. Thecushion 41 d protects wrist 100 by elastically deforming, for example,when the blood pressure measurement device 1 is worn on the wrist 100.

As illustrated in FIGS. 2 to 16, the sensing body 42 includes: a case51, the sensor unit 52, and an adjustment portion 53 for adjusting theposition of the sensor unit 52.

The case 51 has a rectangular box shape with an open surface oppositethe attach portion 41, for example. The case 51 supports the sensor unit52 and the adjustment portion 53. Furthermore, the case 51 is attachedto the attachment portion 41 c in a manner to be movable back and forthin a direction away from the base portion 41 a. As a specific example,the case 51 includes a rotation shaft 51 a rotatably disposed in theattachment portion 41 c. Also, the case 51 includes an engagementportion 51 b that fixes the case 51 to the base portion 41 a when itcomes into contact with the base portion 41 a. The engagement portion 51b, for example, is a projection that engages with an opening provided onthe base portion 41 a and, by being operated, is configured to releasethe engagement with the opening of the base portion 41 a.

Furthermore, the case 51 includes: a first hole portion 51 c where thetube 14 a is disposed, a second hole portion 51 d where the cable 15 ais disposed, a third hole portion 51 e that movably supports a portionof the adjustment portion 53, and a guide groove 51 f that guides themovement of the sensor unit 52.

The first hole portion 51 c and the second hole portion 51 d areprovided on the same side wall of the case 51 adjacent to the devicebody 4 when the device is worn on the wrist 100.

The third hole portion 51 e is provided on a side wall opposite to theside wall of the case 51 where the first hole portion 51 c and thesecond hole portion 51 d are provided. The third hole portion 51 e is arectangular opening that linearly extends in the longitudinal directionof the case 51, or in other words, the circumferential direction of thewrist 100 when the sensor device 5 is attached to the wrist 100.

The guide groove 51 f is provided on the inner surface side of the sidewall of the case 51 provided with the third hole portion 51 e. The guidegroove 51 f includes: a first groove 51 f 1 that extends from an openingend portion of the case 51 to partway toward the ceiling opposite theopening; and a second groove 51 f 2 that extends in a directionorthogonal to the first groove 51 f 1. The second groove 51 f 2 connectsto the first groove 51 f 1 at one end and extends from this end to theother end toward one side in the longitudinal direction of the case 51.

The sensor unit 52 includes: a movable case 61, the air bag 62, thesensor module 63, a movable base 64 that supports the sensor module 63to be movable in one direction with respect to the movable case 61, anda biasing member 65 that biases the sensor module 63 with respect to themovable case 61 in one direction. The sensor unit 52 is supported by thecase 51 in a manner to be movable in a predetermined range in thelongitudinal direction of the case 51 via the adjustment portion 53.

The movable case 61 houses the sensor module 63 and the movable base 64and supports the movable base 64 supporting the sensor module 63 in amanner allowing the movable base 64 to move toward the opening portion41 b of the attach portion 41. The movable case 61 is supported in amanner to be movable in the longitudinal direction of the case 51 insidethe case 51. In addition, a portion of the biasing member 65 is fixed tothe movable case 61.

As a specific example, the movable case 61 has a rectangular box shapewith the surface opposite the attach portion 41 housing the air bag 62and the sensor module 63 being open. The movable case 61 houses the airbag 62, the sensor module 63, and the movable base 64. In the movablecase 61, the air bag 62 is disposed between the ceiling and the movablebase 64. The movable case 61 supports the movable base 64 in a mannerallowing the movable base 64 to move in one direction so that the sensormodule 63 can protrude out from the opening of the movable case 61.

The movable case 61 includes: a guide projection 61 a disposed on theouter surface of the side wall opposite the side wall on which the guidegroove 51 f of the case 51 is provided in a manner allowing the guideprojection 61 a to move in the guide groove 51 f; a fixing portion 61 bin which a portion of the adjustment portion 53 is fixed; and a firstsupport portion 61 c that supports a portion of the biasing member 65.As the guide projection 61 a moves in the second groove 51 f 2, themovable case 61 moves in the longitudinal direction of the case 51.

The first support portion 61 c supports a portion of the biasing member65. For example, the first support portion 61 c is, for example, acylindrical projection. The number of first support portions 61 cprovided is the same as the number of biasing members 65 provided. As aspecific example, two first support portion 61 c are provided. The twofirst support portions 61 c are provided on the inner surface ofopposite side walls of the movable case 61 in a direction orthogonal tothe circumferential direction of the wrist 100 when the sensor device 5is worn on the wrist 100. The first support portions 61 c are disposedat a position separated by a certain distance L from the opening end ofthe movable case 61 disposed on the wrist 100 side. Thus, as illustratedin FIG. 12, a portion of the biasing member 65 is supported at aposition separated the distance L from the opening end of the movablecase 61. In other words, as illustrated in FIG. 12, the biasing member65 is supported by the first support portion 61 c in a manner allowingthe biasing member 65 to rotate about the first support portion 61 c.

The air bag 62 has a bellows-like structure. The air bag 62 is fluidlyconnected to the pump 14 via the tube 14 a. As illustrated in FIGS. 9 to16, the air bag 62 expands in a direction from the ceiling of themovable case 61 toward the opening. When the air bag 62 expands, thesensor module 63 is moved from a position where the sensor module 63 ishoused within the movable case 61 to a position where the sensor module63 projects from the opening of the movable case 61 and comes intocontact with the wrist 100 via the opening portion 41 b of the attachportion 41. The air bag 62 is formed from polyurethane, for example. Theair bag 62 together with the pump 14 and the biasing member 65constitute a pressing mechanism that presses the sensor module 63 towardthe wrist 100.

As illustrated in FIGS. 17 and 18, the sensor module 63 includes: thepressure sensor portion 71, the sensor base 72 that supports thepressure sensor portion 71, a sensor head cover 73 that covers thesensor base 72 and includes an opening 73 a in a region opposite thepressure sensor portion 71, and a soft portion 74 provided in theopening 73 a of the sensor head cover 73.

The sensor module 63 is disposed inside the movable case 61 and issupported by the movable case 61 in a manner allowing the sensor module63 to move in a predetermined movement range in the direction of theceiling and the opening of the movable case 61 opposing one another. Inother words, the sensor module 63 is supported in a manner to be movablewithin the movable case 61, and the movement is restricted by arestriction portion such as a stopper or like when the sensor module 63moves from the opening of the movable case 61 to the position where thesensor module 63 projects out a certain amount or more.

The pressure sensor portion 71 includes: a flexible substrate 71 a, asubstrate 71 b mounted on the flexible substrate 71 a, and a pluralityof the pressure sensitive elements 71 c mounted on the substrate 71 b.The flexible substrate 71 a is connected to the cable 15 a and iselectrically connected to the control board 15 via the cable 15 a.

The substrate 71 b and the plurality of pressure sensitive elements 71 cconstitute a sensor chip. The plurality of pressure sensitive elements71 c are arranged in one direction, forming a pressure sensitive elementarray 71 d. A single or a plurality of the pressure sensitive elementarrays 71 d are provided. In the case in which the plurality of thepressure sensitive element arrays 71 d are provided, the plurality ofpressure sensitive element arrays 71 d are disposed at predeterminedintervals in a direction orthogonal to the arrangement direction of theplurality of pressure sensitive elements 71 c.

Also, the pressure sensor portion 71 is disposed in the sensor base 72such that the direction in which the plurality of pressure sensitiveelements 71 c are arranged is the width direction of the wrist 100. Thepressure sensor portion 71 transmits a pressure value measured by theplurality of pressure sensitive elements 71 c to the control board 15via the cable 15 a.

The sensor base 72 supports the pressure sensor portion 71 and the cable15 a connected to the pressure sensor portion 71. The sensor base 72engages with the sensor head cover 73 on one main surface and supportsthe pressure sensor portion 71 in a region opposite the opening 73 a ofthe sensor head cover 73. The movable base 64 is fixed on the other mainsurface of the sensor base 72.

The sensor head cover 73 comes into contact with the wrist 100 at an endsurface. The soft portion 74 is provided in the opening 73 a of thesensor head cover 73 and protects the pressure sensitive elements 71 c.The opening 73 a has a rectangular shape, for example.

The soft portion 74 is formed, for example, by injecting a relativelysoft resin material such as a silicone resin into the opening 73 a. Anend surface of the soft portion 74 is formed flush with the end surfaceof the sensor head cover 73. Note that it is sufficient that the softportion 74 comes into contact with the wrist 100 and is formed from amaterial that allows the pressure of the radial artery 110 to bedetected by the pressure sensitive elements 71 c, and the thickness,shape that comes into contact with the wrist 100, and material of thesoft portion 74 can be selected as appropriate.

With the blood pressure measurement device 1 worn on the wrist 100, themovable base 64 is supported in the movable case 61 in a manner allowingthe movable base 64 to move in a direction toward and a direction awayfrom the wrist 100. For example, the movable base 64 is configured tomove along the plurality of cylindrical members provided in the movablecase 61, for example. The end portion of the movable base 64 on thewrist 100 side is fixed to the sensor base 72. Thus, the movable base 64supports the sensor base 72 in a manner allowing the sensor base 72 tomove in one direction with respect to the movable case 61. The movablebase 64 includes a second support portion 64 a that is provided on theouter surface of the movable base 64 and supports a portion of thebiasing member 65.

The second support portion 64 a supports a portion of the biasing member65. The second support portion 64 a is, for example, a cylindricalprojection. The number of the second support portions 64 a provided isthe same as the number of biasing members 65 provided. As a specificexample, the second support portion 64 a is provided on the differentouter surfaces of the movable base 64. For example, the second supportportions 64 a are provided on the outer surfaces of the side walls in adirection orthogonal to the circumferential direction of the wrist 100,specifically, the outer surfaces opposite the inner surfaces of oppositeside walls of the movable case 61 provided with the first supportportion 61 c, when the sensor device 5 is worn on the wrist 100. Notethat the positional relationship between the first support portion 61 cand the second support portion 64 a is set as appropriate by the shapeand the like of the biasing member 65.

The biasing member 65 has a neutral state and generates a restoringforce when an external force is applied while in the neutral state. As aspecific example, the biasing member 65 is a torsion spring. A single ora plurality of the biasing members 65 are provided. For example, twobiasing members 65 may be provided in point symmetrical positions aboutthe center of the sensor unit 52 along the movement direction of thesensor module 63.

Both ends of the biasing member 65 are held by the first support portion61 c and the second support portion 64 a. For example, both ends of thebiasing member 65 have an annular shape or a hook-like shape and engagewith the first support portion 61 c and the second support portion 64 a.

As illustrated in FIGS. 10 and 15, the biasing member 65 is in a neutralstate in which a biasing force does not occur when an end of the sensorhead cover 73 of the sensor module 63 is in a neutral point in apredetermined position with respect to the opening portion 41 b of theattach portion 41. Here, the predetermined position is, for example, aposition at which the end of the sensor module 63 projects from theopening portion 41 b. As illustrated in FIGS. 11 and 16, the biasingmember 65 biases the sensor module 63 in a direction toward the wrist100 when the sensor module 63 is on the wrist 100 side of the neutralpoint. Also, as illustrated in FIGS. 9 and 14, the biasing member 65biases the sensor module 63 in a direction away from the wrist 100 whenthe end of the sensor module 63 is at a position separated from thewrist 100 further than the neutral point.

As illustrated in FIG. 19, the adjustment portion 53 is configured toadjust the position of the sensor unit 52, with respect to the case 51,in the circumferential direction of the wrist 100. The adjustmentportion 53 is located on the outer surface of the case 51 and includesan adjustment catch 53 a, the portion of which is fixed to the fixingportion 61 b of the movable case 61 via the third hole portion 51 e.Also, the adjustment portion 53 includes: graduations 53 b providedadjacent to the third hole portion 51 e of the case 51 and aninstruction portion 53 c provided on the adjustment catch 53 a thatindicates the graduations 53 b.

The adjustment catch 53 a is connected to the sensor unit 52 by beingfixed to the movable case 61. The adjustment catch 53 a is configured tomove the sensor unit 52. In other words, the adjustment portion 53 is anadjustment mechanism that, by the adjustment catch 53 a being moved inthe longitudinal direction of the third hole portion 51 e, moves thesensor unit 52 along the second groove 51 f 2 and adjusts the positionof the sensor unit 52 with respect to the case 51.

The graduations 53 b and the instruction portion 53 c are displayportions that display the position of the adjustment catch 53 a, i.e.,the position of the sensor unit 52 connected to the adjustment catch 53a, in a visually recognizable manner.

The fastener 43 includes, for example, one or a plurality of band-likebands and a fixing member such as a hook-and-loop fastener that securesthe band wrapped around the wrist 100. The fastener 43 fixes the attachportion 41 and the sensing body 42 to the wrist 100. Note that thefastener 43 may be composed of: a first belt referred to as a parentthat includes a buckle; and a second belt referred to as a pointed endthat is fixed to the buckle. Also, the fastener 43 may further have aconfiguration in which the case 51 is fixed to the attach portion 41 bythe fastener 43 being wrapped around the case 51.

In other words, the fastener 43 is configured to prevent the case 51from moving in a direction away from the attach portion 41 when thereaction force, when the sensor module 63 presses against the wrist 100due to the expansion of the air bag 62, acts on the movable case 61 andwhen the case 51 is directly pressed by the movable case 61 orindirectly pressed via the adjustment catch 53 a from the movable case61.

Next, an example of measurement of a blood pressure value using theblood pressure measurement device 1 will be described using FIGS. 20 to23. FIG. 20 is a flowchart illustrating an example of a blood pressuremeasurement using the blood pressure measurement device 1, illustratingboth the operation of the user and the operation of the control unit 33.FIGS. 21 to 23 are explanatory diagrams illustrating an example of bloodpressure measurement using the blood pressure measurement device 1.

First, the user searches by palpation for the position of the radialartery 110 of the wrist 100 (step ST1). For example, at this time, avisible line may be drawn on the skin above the radial artery 110 with apen.

The user then separates the sensing body 42 of the sensor device 5 fromthe attach portion 41. In the present embodiment, the user operates theengagement portion 51 b to release the engagement of the case 51 withthe base portion 41 a and rotates the sensing body 42 about the rotationshaft 51 a in a direction away from the attach portion 41.

The user then attaches the device body 4 and the sensor device 5 asillustrated in FIG. 21 (step ST2). As a specific example, the user firstpasses the wrist 100 through the body fastener 16 of the device body 4and the fastener 43 of the sensor device 5 and places the device body 4and the sensor device 5 at a predetermined position on the wrist 100.Next, the user tightens the body fastener 16 of the device body 4 andfixes the device body 4 to the wrist 100. Here, in a case ofconfiguration in which a cuff is provided on the body fastener 16 of thedevice body 4, the user checks to see whether the skin of the wrist 100is caught in the body fastener 16 (cuff) and whether the body fastener16 (cuff) is too loose. Next, the user adjusts the position of thesensor device 5 so that the opening portion 41 b of the attach portion41 of the sensor device 5 is located at the radial artery 110 of thewrist 100. In addition, the user tightens the fastener 43 of the sensordevice 5, and the sensor device 5 is fixed to the wrist 100, with theradial artery 110 held at the position of the opening portion 41 b.

Next, as illustrated in FIG. 22, the user palpates the wrist 100 fromthe opening portion 41 b of the attach portion 41 (step ST3) and checksagain that the radial artery 110 is located at the opening portion 41 b.Then, as illustrated in FIG. 23, the user rotates the sensing body 42 ina direction toward the attach portion 41 and fixes the sensing body 42to the attach portion 41 via the engagement portion 51 b. Note that whenthe position of the sensing body 42 is misaligned with the radial artery110, the user operates the adjustment catch 53 a and adjusts theposition of the sensing body 42.

Note that at this time, the biasing member 65 biases the sensor module63 away from the wrist 100, and as illustrated in FIG. 14, the sensormodule 63 is located at a position separated from the wrist 100 furtherthan the neutral point and located closer to the case 51 than theopening portion 41 b. Thus, as illustrated in FIG. 14, the sensor headcover 73 of the sensor module 63 is separated away from the wrist 100.

Next, the user operates the operation portion 12 to send an instructionto measure the blood pressure. The control unit 33 measures the bloodpressure on the basis of the blood pressure measurement instruction(step ST4). At this time, the control unit 33 drives and controls thepump 14, and, as illustrated in FIGS. 10 and 15, the air bag 62 isexpanded, moving the sensor module 63 progressively toward the wrist 100from a state of being housed inside the movable case 61 as illustratedin FIGS. 9 and 14. Thus, as illustrated in FIGS. 11 and 16, the sensorhead cover 73 and soft portion 74 of the sensor module 63 press againstthe region in which the radial artery 110 of the wrist 100 is found.

At this time, the sensor module 63 moves beyond the neutral pointillustrated in FIG. 15 toward the wrist 100 as illustrated in FIG. 16.One end of the biasing member 65 is rotatably supported by the firstsupport portion 61 c, and the movable case 61 is fixed against the wrist100. Thus, the biasing member 65 rotates about the first support portion61 c as the sensor module 63 moves, moving from the orientation of theupper diagram in FIG. 12 (FIG. 9), through the orientation of the middlediagram in FIG. 12 (FIG. 10), to the orientation of the lower diagram ofFIG. 12 (FIG. 11). This causes the biasing member 65 to bias the sensormodule 63 in a direction toward the wrist 100 due to a change in thedirection of bias, passing through the neutral state when the sensormodule 63 moves beyond the neutral point. As a result, the sensor module63 presses against the wrist 100 due to the force applied by the air bag62 and the biasing member 65.

In this way, by pressing the sensor head cover 73 and the soft portion74 against this region of the wrist 100, the radial artery 110 ispressed with an appropriate amount of pressure so that a flat portion isformed in the radial artery 110, as illustrated in FIG. 16. In thisstate, the pressure sensitive elements 71 c of the pressure sensorportion 71 measure the pressure pulse waves.

Note that the control unit 33 obtains the blood pressure via thetonometry method from the pressure pulse waves of the radial artery 110detected by the pressure sensor portion 71. Note that prior to bloodpressure measurement, the control unit 33 may perform a blood pressuremeasurement for calibration on the basis of program data stored in thestorage unit 32 or may perform a check to determine whether or not theworn state of the device body 4 and/or the sensor device 5 and theposition of the pressure sensor portion 71 are correct.

According to the blood pressure measurement device 1 configured in thismanner, the biasing member 65 biases the sensor module 63 in a directionaway from the wrist 100 with force along one direction when the sensorhead cover 73 is positioned further away from the wrist 100 than theneutral point.

With this configuration, in the blood pressure measurement device 1,after blood pressure measurement, the sensor module 63 moves to theneutral point due to a reaction force from the wrist 100, and then thesensor module 63 is biased by the biasing member 65 and moves from theneutral point until the sensor module 63 is housed in the movable case61.

This causes the sensor module 63 to be located in the movable case 61more so than in the opening 41 b, and when the worn blood pressuremeasurement device 1 is removed, the sensor module 63 of the sensordevice 5 does not project outward.

As a result, the sensor module 63 does not interfere with the wrist 100and other configurations, and thus the wrist 100 is not burdened. Also,damage caused by interference with other configurations can beprevented. In addition, by the biasing member 65, being biased in thedirection of housing within the movable case 61, the sensor module 63 isconfigured to move back and forth in one direction relative to themovable case 61 by the air bag 62 and the biasing member 65.

Also, according to the blood pressure measurement device 1, the neutralpoint is configured to be located where the end of the sensor module 63projects from the opening 41 b. With this configuration, after the endof the blood pressure measurement, the blood pressure measurement device1 can use the reaction force from the wrist 100 to move the sensormodule 63 to a position separated from the wrist 100 further than theneutral point. Thus, the biasing direction of the biasing member 65 canbe easily switched from the direction of pressing the sensor module 63toward the wrist to a direction of biasing the sensor module 63 awayfrom the wrist 100.

Also, according to the blood pressure measurement device 1, the biasingmember 65 is configured to bias the sensor module 63 in a directiontoward the wrist 100 with force along one direction, with the neutralpoint of the sensor module 63 acting as the boundary, when the sensorhead cover 73 is positioned closer to the wrist 100 than the neutralpoint. According to this configuration, when the blood pressuremeasurement device 1 is used for blood pressure measurement, the air bag62 and the biasing member 65 press the sensor module 63 toward the wrist100, allowing the sensor head cover 73 to be suitably pressed againstthe wrist 100.

As a specific example, a relationship between stroke (mm) and pressingforce (N) of a Comparative Example including the air bag 62 and nobiasing member 65 and an Example including the air bag 62 and thebiasing member 65 will be described using FIG. 24. Note that theconfigurations other than the presence or absence of the biasing member65 are the same in both the Example and the Comparative Example, andeach of the blood pressure measurement devices 1 controls the pump 14 sothat the pressure inside the air bag 62 is 250 mmHg. Also, the 0 mmstroke position is where the air bag 62 is not inflated and the sensormodule 63 is in a position separated from the wrist 100 further than theneutral point. The term stroke is the amount of movement of the sensormodule 63 from that position.

As illustrated in FIG. 24, the blood pressure measurement device of theComparative Example does not include the biasing member 65. Thus, thepressing force progressively decreases as the stroke increases. This isbecause when the air bag 62 expands, the side surface of the air bag 62in the direction orthogonal to the expansion direction also expands. Incontrast, as illustrated in FIG. 24, with the blood pressure measurementdevice 1 of the Example, the biasing force caused by the biasing member65 increases as the stroke increases. In this way, the biasing member 65compensates for a decrease in the pressing force caused by expansion ofthe air bag 62, and the pressing force can be made substantiallyconstant. As a result, the blood pressure measurement device 1 canprevent a decrease in the pressing force when the stroke increases.

Furthermore, FIG. 25 illustrates the relationship between stroke andpressing force for Example 1, Example 2, and Example 3 in which thetarget value of the internal pressure of the air bag 62 is set to 250mmHg, 200 mmHg, and 150 mmHg, respectively. As can be seen from FIG. 25,by providing the biasing member 65, the blood pressure measurementdevice 1 achieves the same effect regardless of the target value of theinternal pressure of the air bag 62. In other words, as in Example 1 toExample 3, while there is a difference in pressing force due to thedifferent target values of the internal pressure of the air bag 62, thepressing force can be made substantially constant with respect to thestroke by providing the biasing member 65.

In addition, by setting the biasing member 65, the blood pressuremeasurement device 1 can increase the pressing force, when the strokeincreases, by the air bag 62 and the biasing member 65, which constitutethe pressing mechanism, and can set the pressing force to maximum whenpressing the wrist 100.

In addition, because the blood pressure measurement device 1 can set theforce pressing the wrist 100 to a preferred force with a simpleconfiguration in which the biasing member 65 is provided, it is notnecessary to increase the capacity of the pump 14 or complicate thecontrol of the pump 14. In addition, in the blood pressure measurementdevice 1, because the sensor module 63 can press the wrist 100 with anappropriate pressing force, a flat portion can be suitably made in theradial artery 110, and the accuracy of the blood pressure measurementcan be improved.

Also, the blood pressure measurement device 1 has a simple configurationin which the sensor module 63 can be biased with the bias member 65being a torsion spring. Thus, an increase in manufacturing cost can beprevented. Furthermore, because a plurality of the biasing members 65are provided, the size of each of the plurality of biasing members 65needed to create a desired biasing force can be made small and used assuch, compared to a configuration in which a single biasing member isprovided. Thus, the sensor device 5 can keep the space and configurationsmall for installing and supporting the biasing members 65.

In addition, the sensor device 5 includes a pair of the biasing members65 disposed with point symmetry on either side of the sensor module 63.Thus, the sensor device 5 can uniformly apply a biasing force to thesensor module 63. This allows the sensor device 5 to stably move thesensor module 63 because the biasing force of the bias member 65 appliedthereto moves along one direction. That is, by applying a biasing forceto a portion of the sensor module 63, a force in a direction other thanthe movement direction of the sensor module 63 may be applied to thesensor module 63. However, with the present configuration, a biasingforce along the movement direction of the sensor module 63 can beapplied to the sensor module 63.

Also, the blood pressure measurement device 1 can be configured to biasthe sensor module 63 by the biasing member 65 to move the sensor module63 back and forth in one direction with a simple configuration. In otherwords, the wrist 100 can be palpated from the opening portion 41 b, and,when the sensor device 5 of the blood pressure measurement device 1 isworn on the wrist 100, the sensor device 5 is worn in an ad-lib state onthe wrist 100 and the radial artery 110 is found by palpation;thereafter, the sensor device 5 is adjusted in position and wornproperly. As a result, the blood pressure measurement device 1 can beeasily worn at the appropriate position.

In addition, because the sensor device 5 has a configuration thatincludes the adjustment portion 53, the adjustment catch 53 a can beoperated even after the sensor device 5 is worn properly on the wrist100. This allows the position of the sensor unit 52 with respect to theradial artery 110 to be adjusted, which further allows the pressure ofthe radial artery 110 to be measured at a suitable position.

Furthermore, the sensor device 5 has a configuration in which thesensing body 42 is configured to be moved in a direction away from theattach portion 41 and in which the sensing body 42 rotates away from theattach portion 41 about an axis. Thus, when the sensing body 42 ismoved, the sensor module 63 provided on the sensing body 42 moves in adirection away from the opening portion 41 b of the attach portion 41.

This can prevent the sensor module 63 from moving while in contact withthe wrist 100 and the attach portion 41 when the sensing body 42 ismoved with respect to the attach portion 41. Specifically, the sensorunit 52 measures the blood pressure, with the sensor head cover 73 andthe soft portion 74 of the sensor module 63 projecting from the openingof the movable case 61, at a position where the wrist 100 can beappropriately pressed via the air bag 62.

Even when the sensing body 42 is moved with respect to the attachportion 41 in this state, in the sensing body 42, the sensor module 63moves in a direction away from the wrist 100. Thus, the sensing body 42cannot move in a state of the end surface of the sensor head cover 73and the soft portion 74 being in contact with the wrist 100 or theattach portion 41. As a result, when the sensing body 42 is moved,damage caused by the sensor module 63 interfering other configurationsor the wrist 100 and a load on the wrist 100 can be prevented.

In this way, because the sensor device 5 is provided with the openingportion 41 b with a shape that allows palpation through the attachportion 41 and the sensing body 42 is configured to move in a directionaway from the attach portion 41 and the wrist 100, damage to the sensormodule 63 can be prevented and safety can be improved.

Also, the sensor device 5 has a configuration in which the sensing body42 rotates with respect to the attach portion 41 at one end side in thelongitudinal direction of the attach portion 41. Thus, substantially theentire region of the upper surface of the attach portion 41 can beexposed to the outside. As a result, the opening portion 41 b of theattach portion 41 is completely exposed, allowing the size of the shapeof the opening portion 41 b required for palpation to be kept as smallas possible. Furthermore, in the sensor device 5, a rail configurationfor sliding the sensing body 42 with respect to the attach portion 41;or a configuration for supporting the sensing body 42 on the attachportion 41 after sliding are not necessary. Thus, the shape in the widthdirection of the wrist 100 of the sensor device 5 can be kept as smallas possible. This allows the sensor device 5 to be made compact.

As described above, according to the blood pressure measurement device 1according to an embodiment of the present invention, the attach portion41 is provided with the opening 41 b having a shape that allows forpalpation, and the sensing body 42 that rotates about a single axis withrespect to the attach portion 41 is provided. This allows palpation ofthe wrist when the device is worn and can prevent the sensor module 63from being damaged.

Note that the present invention is not limited to the embodimentdescribed above. The biasing member 65 is not limited to being a torsionspring and may be composed of a different elastic body. The biasingmember 65 is only required to have a configuration that is able toelastically deform due to an external force in one direction and torestore its shape in a direction opposite to the direction the externalforce is applied. For example, as illustrated in FIG. 26, the biasingmember 65 may be formed from a resin material and be configured to biasthe sensor module 63 using a so-called rubber-switch-shaped elasticbody. When the biasing member 65 is formed from a resin material in thismanner, the resin material can have various shapes depending on themolding die. Thus, the options for the positions and shapes that can bedisposed between the movable case 61 and the sensor module 63 areincreased, so the design has a high degree of freedom, forming can beperformed with a mold, and manufacturing is made easy.

Also, in the example described above, the biasing member 65 describes aconfiguration in which a different bias force is applied to the sensormodule 63, with the neutral point of the sensor module 63 acting as theboundary. However, no such limitation is intended. For example, thebiasing member 65 may be configured such that the sensor module 63 isseparated from the wrist 100 and biases the sensor module 63 only in thedirection in which he sensor module 63 is housed in the movable case 61.This configuration may allow the sensor module 63 to be pressed by theair bag 62 when the wrist 100 is pressed by the sensor head cover 73 andmay allow the sensor module 63 to be biased by the biasing member 65when housed. Similarly, the biasing member 65 may be configured as apart of the pressing mechanism, with the air bag 62, that is configuredto bias the sensor module 63 when pressing the wrist 100.

Also, in the example described above, the blood pressure measurementdevice 1 has a configuration in which the device body 4 and the sensordevice 5 are different bodies. However, no such limitation is intended.For example, as illustrated in FIGS. 27 and 28, the blood pressuremeasurement device 1 may have a configuration in which the device body 4and the sensor device 5 are integrally formed. The blood pressuremeasurement device 1 with such a configuration, for example, may haveconfiguration in which the operation portion 12, the display portion 13,the pump 14, and the control board 15 used in the device body 4 areprovided in the case 51 of the sensing body 42.

Also, in the example described above, the blood pressure measurementdevice 1 has a configuration in which the sensing body 42 moves in adirection away and a direction toward the attach portion 41 by thesensing body 42 rotating with respect to the attach portion 41 about anaxis. However, no such limitation is intended. For example, asillustrated in FIG. 29, the blood pressure measurement device 1 may havea configuration in which the sensing body 42 moves in a direction awayand a direction toward the attach portion 41 by the attach portion 41and the sensing body 42 being separated. In the case in which the bloodpressure measurement device 1 has this configuration, the engagementportions 51 b are provided at a plurality of positions on the case 51 ofthe sensing body 42, and the sensing body 42 engages with the attachportion 41 at these positions.

Also, in the examples described above, the blood pressure measurementdevice 1 has a configuration that measures the pressure of the radialartery 110 and that obtains the blood pressure by the tonometry method.

However, no such limitation is intended. In another example, thepressure of the ulnar artery 112 is measured. The blood pressuremeasurement device 1 may also have a configuration in which the bloodpressure is obtains via a method other than the tonometry method. Inother words, the blood pressure measurement device 1 is only required tohave a configuration in which the sensor module 63 that comes intocontact with the wrist 100 is capable of moving with respect to theopening portion 41 b of the attach portion 41 and the wrist 100. Inaddition, similarly, the present invention is not limited to a devicefor measuring blood pressure and may be applied to other devices usingother measurement methods such as devices for measuring pulse waves.

In the examples described above, a configuration is described in whichthe opening portion 41 b of the attach portion 41 has a shape thatallows for palpation of the wrist 100. However, no such limitation isintended. That is, as long as the opening portion 41 b of the attachportion 41 has a shape that allows the sensor unit 52 to come intocontact with wrist 100 beyond the opening portion 41 b, in a range inwhich position is adjusted by the adjustment portion 53, a shape thatdoes not allow palpation of the wrist 100 may be used.

Also, in the example described above, the sensor unit 52 has aconfiguration in which the sensor base 72 of the sensor module 63 issupported by the movable base 64 in a manner allowing the sensor base 72to move within the movable case 61. However, no such limitation isintended. For example, the movable base 64 may be integrally formed withthe sensor base 72 of the sensor module 63.

In other words, the embodiments described above are merely examples ofthe present invention in all respects. Of course, various modificationsand variations can be made without departing from the scope of thepresent invention. Thus, specific configurations in accordance with anembodiment may be adopted as appropriate at the time of carrying out thepresent invention.

Note that the present invention is not limited to the embodimentsdescribed above, various embodiments and modifications within the spiritof invention are possible. Furthermore, each of the embodiments may becombined as appropriate to obtain the combined effects of theembodiments. Also, the embodiments described above include variousstages of invention, and various inventions may be obtained byappropriately combining the multiple configuration requirementsdisclosed.

REFERENCE SIGNS LIST

-   1 Blood pressure measurement device-   4 Device body-   5 Sensor device-   11 Body case-   12 Operation portion-   13 Display portion-   14 Pump-   14 a Tube-   15 Control board-   15 a Cable-   16 Body fastener-   21 Button-   31 Communication unit-   32 Storage unit-   33 Control unit-   41 Attach portion-   41 a Base portion-   41 b Opening portion-   41 c Attachment portion-   41 d Cushion-   42 Sensing body-   43 Fastener-   51 Case-   51 a Rotation shaft-   51 b Engagement portion-   51 c First hole portion-   51 d Second hole portion-   51 e Third hole portion-   51 f Guide groove-   51 f 1 First groove-   51 f 2 Second groove-   52 Sensor unit-   53 Adjustment portion-   53 b Graduations-   53 c Instruction portion-   61 Movable case (case)-   61 a Guide projection-   61 b Fixing portion-   61 c First support portion-   62 Air bag-   63 Sensor module-   64 Movable base-   64 a Second support portion-   65 Biasing member-   71 Pressure sensor portion-   71 a Flexible substrate-   71 b Substrate-   71 c Pressure sensitive element-   71 d Pressure sensitive element array-   72 Sensor base-   73 Sensor head cover-   73 a Opening-   74 Soft portion-   100 Wrist-   110 Radial artery-   111 Radius-   112 Ulnar artery-   113 Ulna-   114 Tendon

1. A blood pressure measurement device, comprising: an attach portionincluding: an opening portion provided at a position opposite a regionwhere one artery of a wrist is found and an end surface that curvesconforming to a shape in a circumferential direction of a portion of thewrist; a fastener provided on the attach portion; and a sensing bodyincluding: a sensor unit disposed opposite the opening portion, thesensor unit including a sensor module that comes into contact with theregion where the one artery of the wrist is found and an air bag thatpresses the sensor module toward the wrist by expanding when the deviceis worn on the wrist, a case that houses the sensor module in a mannerallowing the sensor module to move in one direction with respect to theopening portion, and a biasing member that biases the sensor module in adirection toward the wrist.
 2. The blood pressure measurement deviceaccording to claim 1, wherein the biasing member biases the sensormodule in the direction toward the wrist when an end of the sensormodule is located on a side of the wrist from a neutral point, theneutral point being a predetermined position with respect to the openingportion, and biases the sensor module in a direction away from the wristwhen the end of the sensor module is located at a position further awayfrom the wrist than the neutral point.
 3. The blood pressure measurementdevice according to claim 2, wherein the neutral point is a positionwhere the end of the sensor module projects from the opening portion. 4.The blood pressure measurement device according to claim 1, wherein thebiasing member is a torsion spring.
 5. The blood pressure measurementdevice according to claim 4, wherein a plurality of the torsion springsare provided.
 6. The blood pressure measurement device according toclaim 5, wherein two of the torsion springs are provided on either sideof the sensor module in a direction orthogonal to the circumferentialdirection of the wrist when the device is worn on the wrist, and one endof each of the torsion springs is fixed to the sensor module and another end of each of the torsion springs is fixed to the case.
 7. Theblood pressure measurement device according to claim 1, wherein thebiasing member is formed from a resin material and deforms due to anexternal force in one direction and restores its shape in a directionopposite to the direction in which the external force is applied.
 8. Theblood pressure measurement device according to claim 2, wherein thebiasing member is a torsion spring.
 9. The blood pressure measurementdevice according to claim 3, wherein the biasing member is a torsionspring.
 10. The blood pressure measurement device according to claim 2,wherein the biasing member is formed from a resin material and deformsdue to an external force in one direction and restores its shape in adirection opposite to the direction in which the external force isapplied.
 11. The blood pressure measurement device according to claim 3,wherein the biasing member is formed from a resin material and deformsdue to an external force in one direction and restores its shape in adirection opposite to the direction in which the external force isapplied.